Maliketh, The Black Blade

Deathtouch, Vigilance
When Maliketh, The Black Blade tranforms,
destroy all tapped creatures you don't control.
When Maliketh, The Black Blade deals combat
damage to an opponent, they lose X life, where
X is their life total minus 20.
Opponents' life totals cannot exceed 20 for the
rest of the game.